// Echo2 prints its command-line arguments.
package main

import (
    "fmt"
	"os"
	"strconv"
)

// 练习 1.2： 修改echo程序，使其打印每个参数的索引和值，每个一行。

func main() {
    s, sep := "", ""
    for index, arg := range os.Args[1:] {
        s += sep + strconv.Itoa(index) + ": " + arg
        sep = "\n"
    }
    fmt.Println(s)
}